5′-inosinic acid is an intermediate material of the metabolic system of nucleic acid biosynthesis, which is used in a variety of fields, like foods and medicines, and in various kinds of medical areas and is important in animal and plant physiology. In particular, 5′-inosinic acid is a nucleic acid-type seasoning that has synergic effect when used with sodium glutamate.
Processes for producing 5′-inosinic acid by direct fermentation have been known in this field, and the important key in economical aspects was to produce 5′-inosinic acid in a high concentration and yield.